The present invention relates to a developing device for supplying a toner to an image carrier, with an electrostatic latent image thereon, to develop the latent image, and more specifically to a method of packing a developing device at the time of shipment from the factory, and the packed developing device.
In image forming apparatuses, such as electronic copying machines, an electrostatic latent image is formed on a photosensitive drum, and a powder toner is applied to the latent image, thereby developing the image. After the development, the toner image is transferred to a paper sheet so that an image is formed on the sheet.
In the image forming apparatuses of this type, a developing agent of the so-called two-component type may sometimes be used, which is formed of a mixture of a powder toner and a carrier for carrying the toner. When using the two-component developing agent, the density of a developed image varies, depending on the mixture ratio between toner and carrier. In order to obtain a developing-agent image with a constant or stable density, therefore, the mixture ratio must be kept constant. Since the toner is consumed in the developing process, the toner content (or mixture ratio between toner and carrier) of the developing agent varies gradually. Accordingly, the developing device of this type is provided with an auto-toner adjuster, which automatically detects the mixture ratio between toner and carrier, and supplies the toner in response to a detection signal, during copying operation.
The auto-toner adjuster is designed, however, so as to directly detect the toner-carrier mixture ratio, on the basis of a detected value of the permeability of the developing agent, the quantity of light reflected by the toner only, etc. It is therefore necessary to set some reference values (initial adjustment).
Conventionally, the initial adjustment of the developing device is performed in accordance with the developing agent used, by a serviceman, who visits the user and installs the image forming apparatus, after the apparatus is delivered to the user. This is done because the developing agent, whose properties vary delicately with lots, requires an initial adjustment for each lot.
The initial adjustment, however, requires much labor, by a skilled technician. If the image forming apparatus is operated without the initial adjustment, or if the adjustment is performed in an improper manner, this will cost more time and labor. If the initial adjustment is skipped, in particular, a blade will be rubbed directly against a developing roller in the developing device, so that the blade or photosensitive drum will possibly be damaged.
If the auto-toner adjuster is regulated at the factory, before the shipment of the image forming apparatus, the developing agent, used for the adjustment, cannot be kept stored in the developing device when the apparatus is shipped. The reason is that if the image forming apparatus is shipped with the developing agent in the developing device, the agent will be spilled, by vibration during transport, from a feed port, through which it is to be fed to the photosensitive drum of the apparatus.